This is really a fantastic game! It is well polished and a lot of fun, and it really leverages its IP to make the gameplay suit the story. Spiderman games, for example, mostly feel like "GTA except you're Spiderman," to me, but this game was very well matched to the Batman franchise. I'll rattle off a few of my favorite things...
1) The property itself. This game combines the wonderful storytelling of the animated series (along with most of the voice cast) with the dark, violent world that the new movies portray so well. It uses the lore from the comics as a pillar, I think, on which the whole story is rooted. You can see influences from Batman Begins and The Dark Knight in the technology (like Batman's detective cowl vision) as well as in the musical score. And there are even homages here and there to the Burton films. Basically, the game pulls from just about everything the entire Batman franchise has to offer, and ties it all together really well (a complicated task, considering the multitude of sources). Everything in the game feels like it belongs in the world.
2) The freedom in gameplay. I really feel like this game gives a lot of freedom for the player to approach situations in different ways. The custom upgrade unlocks really help with this, since you can sort of focus on your own play style when choosing what to unlock. This was really fun when playing with Will (we traded off here and there) - I really enjoyed stealthing and setting traps and sneaking about, but Will is a better brawler overall. As far as the overarching gameplay, I felt like there was a great balance between the objective-driven story and the opportunities to explore (and find all those Riddler challenges - they can be a little addictive, I'm not gonna lie)
3) The setting of Arkham Island. I'm really glad that they limited the play space just to Arkham, because I feel like it helped give the world a grander sense of scale. It sounds a little counter-intuitive, but if they'd had the game such that you could go all over Gotham city, it would inevitably feel shrunken down. They were able to stick to Arkham and still get a fantastic variety in play spaces; I think it was very cleverly done.
4) The Scarecrow moments. OMFG, Scarecrow gives me nightmares.
Well done, Batman! You were made into a great game. And well done Rocksteady Studios! May you reap in the many rewards you deserve from the experience you created.
I'd say anyone should give this game a shot, Batman fan or no, but some of you in particular would really love it (I'm lookin at you, Ken).